For the past five hundred years, the Cahills have been silently changing the world. Their desperate hunt for the 39 Clues lies behind some of history’s biggest enigmas—the curse of the Hope diamond, the race to summit Mt. Everest, the wild life and death of Harry Houdini. And now—finally—the secrets are out. With an introduction by Rick Riordan, The 39 Clues: The Black Book of Buried Secrets reveals the shocking truth about history’s most notorious family, including: